Automatic controlling mechanism for refrigerating systems.



E. CARPENTER & P. M. KIMBALL. AUTOMATIC CONTROLLING MECHANISM FORREFRIGERATING SYSTEMS.

APPLICATION TIL ED MAR-.15. 1007.

2 SHEETSSHEET I Patented J an. 17, 1911.

wa- 1M0 me o I E. CARPENTER & F. M. KIMBALL. AUTOMATIC GONTROLLINGMECHANISM FOR REFRIGERATING SYSTEMS.

APPLICATION FILED MAR. 15, 1907. 981 ,840. Patented Jan. 17,1911.

2 SHEETS-SHEET 2.

ziz nedves five/2&7

, ZL W (9M 9 4. WI. JQQ/M UNITED STATES PATENT OFFICE.

EUGENE CARPENTER, NEWTON, AND FRED 'KIMBALL, OF SOMERVILLE, MASSA-CHUSETTS, ASSIGNORS TO THE AUTOMATIC REFBIGERATING COMPANY, OF JERSEYCITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC CONTROLLING MECHANISM FOR REFRIGERATING SYSTEMS.

T 0 all whom it may concern:

Be it known that we, EUGENE CARPENTER.

paratus involves a conduit for the rctrigerant, whose low pressure sideis located in the space to be refrigerated, whether the same be a coldstorage chamber for example, or the cooling tank of a brine circulatingsys tem; a pump' for compressing and circulating the refrigerant in saidconduit,'a motor (usually electric) t'or operating said pump, and 'athermostat or other equivalent device in the refrigerating chamber orspace to control the stopping and starting of the motor and therefore ofthe refrigerant circulating pump, in accordance with ten'iperature condit-ions in said chamber or space. In such systems, situated as they arein a great variety of widely detached locations, the water supplydepended upon for the condenser upon the high pressure side of therefrigerant circuit is not uniforn'ily reliable or constant, and shouldits flow be diminished or cut oil, or should for any reason a properlyreduced temperature be unobtainable on the high pressure side of theretrige ant circuit, an abnormal pressure may develop in the latter,interrupting the proper normal operation oi the apparatus, or evenresulting in the accumulation of dangerous pressure.

The object oi our invention is to prevent absolutely the operation ofthe pump, and to throw it out of operation it it is in opera- .tion,automatically, should abnormal presill sures develop the refrigerantcircuit, or should the condenser water supply fall to an inmlequateamount. and our invention particularly ontemplates the coaction of ooththe rctri nt pressure and condenser fluid pressure ud any other fluidpressure whose abnormality might be prejudicial to the Specification ofLetters Patent.

Application filed March 15, 1907.

f said switches b of circuit, and the pump absolutely pre- Patented Jan.17, 1911. Serial No. 362,518. A

proper operation of the system) in controlling the motor-so that theyhave to be in substantially normal state inorder that the motor shallstart or continue in operation and the development of abnormal pressurein either (or any) conduit will automatically stop the motor.

In the forms of our invention here illustrated and more particularlydescribed, the driving power for the pump is supposed to be an electricmotor, but the invention is not to be understood as so limited, for thecontrolling devices here shown are applicable to other forms of motivepower, and the member controlled thereby and itself c0n-- trolling themotor, may be a switch as here shown, or the controlling lever or otherdevice of a water, steam or gas motor.

In the accompanying drawing Figure l exhibits partly in diagram andpartly in sectional elevation, so much of the apparatus only as isnecessary to an understanding of our invention in a form employing twoseparate switches arranged in series in the motor circuit. Figs. 2 and 3show respectively in side and plan views, a form of our inventionwherein a plurality of controlling devices control one switch. The abovefigures show two forms of the invention, in which the circuit is closedmanually and automatically controlled only as to the opening oi thecircuit. Fig. at shows in diagram a further and preferred development ofthe system in which both the opening and the closing of the circuit arecontrolled by the fluid pressure devices.

Referring to Fig. 1; 1, 2, are members controlling the stopping andstarting of the refrigerant circulating pump. As here shown, they arehand knife-blade switches pivoted at 3, as, either one alongside of the.

other on the same base plate, or on separate base plates 5, 6, as hereshown. They are so hung and weighted or spring actuated by leaf spring aas to be held normally away from their contacts, but may be shifted byhand to engage-a series of contacts 7, S, 9, l0, arranges in series incircuit 11, which mayiuclude i pump motor or the controlling circuitthereof. Should either of open, the motor cut out vented from operation.Only two switches are here shown, but it will be apparent, that phragman additional one may be supplied for each part of the refrigeratingsystem, an abnormal or changed condition in which may render necessaryor desirable the stopping of the motor and the consequent stoppage 0circulation of the refrigerant. One of. said switches may for example becontrolled by the pressure in the condenser-water conduit, the other bythe ressure in the high pressure side of the re rigerant conduit. Athird might be controlled by the low pressure side of the latter.Various means may be adopted to this end, and those herein shown areintended to be illustrative merely, and may be modified to suit therequirements. As here shown, each switch arm 1, 2, is actuated by springa, and has a shoulder 12, 13, engaged by the short arm or pawl 14, 15 ofan angle lever pivoted to the base plate and connected at the end of itslong arm 16, 17 to the pin 18,19 of the diaphragm or piston 20, 21 in apressure chamber 22, 23. The angle levers-are so actuated by springs 14or other equivalent means, as to prevent the short arms thereof engagingwith the shoulders of the switch levers except at such times as thediaphragms are in position due to normal operation of the system. Thepressure chambers may be in various forms, for example, a cylinder andpiston, a Bourdon tube, or equivalent construction may be used; but asthe simplest form, we have shown and prefer the inclosed ressure chamberhere illustrated, with fiexi le diaphragm directly controlling the.pin18, 19.

The pressure chamber 22 is, on the side of the diaphragm opposite fromthe controlling pin 18, .connected, as by pipe 24, with the condenserwater conduit,while the opposite side of the pressure chamber 23 isconnected as by pipe 25 with the high pressure side of the refrigerantcirculating conduit. Thus one of the diaphragms' is controlled {by'thepressure of the water supply to the condenser, and the other by therefrigerant circulation, both of which have to be in roper condition 111order that the system s al operate. Referring for example to the switch1 and its controlling ressure chamber, it will be seen that normally thepressure in pipe 24 will hold the diaphragm 20to the position shown infull lines holding the locking awl 14 in position to engage the shoulder0)? switch arm 1, but

llf there is an inadequate pressure of water in the pipe 24,diapxhragm20 will be drawn in to the position s own in dotted lines, theits switch and if the latter is closed it cannot remain closed; also if,with the pump in operation, pressure develops in the pipe 24, thediamovin into the position shown in dotted lines, wil disen age the pawl14 from the switch, and the e ectric circuit will be automaticallyopened Referring. to switch cuit.

low

2, it will be seen that if when said switch is manipulated to close it,the pressure in the pipe 25 is abnormally high, the diaphragm 21 will bein the position shown in dotted lines, and the switch cannot be heldclosed andthat the pump will not be started, and if with the pump inoperation such abnormal pressure develops in the refri erant circuit,the switch will be automatical y unlatched and will open the motorcircuit and stop the pump. A duplicate of switch 1 and its controllingmechanism may, as already stated, be arranged in series therewith, butconnected to the low pressure side of the refrigerant conduit so thatabnormal drop of pressure therein would also open the cir- The circuitwould in that case be controlled by all threeswitches, all of thecontrolling pressures of which would have to be in normal condition inorder that the motor mi ht be started and kept in operation.

ither switch 1, 2, may be controlled by several pressure chambers. Forexample we have illustrated in Fi s. 2 and 3 how switch 1 may becontrolled by pressure in two or more pressure chambers in several fluidcirculating conduits. \Vith this form of the mechanism switch 2,arranged in series with switch 1 may still be employed, and becontrolled by other fiuid pressure devices or it may be omitted and themotor circuit be controlledby the single switch 1 controlled by all thefluid pressure circuits whose liability to abnormal conditions -might beprejudicial to the proper operation of the system. In Figs. 2, 3, asingle controlling switch or lever 1 is employed having the pivotedlocking pawl lever 14, 16 engaging the shoulder 12 thereof. The spring26 holds and returns the pawl lever to engaging osition, so that in thenormal operation 0 the apparatus, the pawl 14 will engage and lock theswitch whenever it is closed. The long arm 16 of the'pawl lever enters ayoke 27 fixed to the base plate. Each diaphragm pin 28, 29 of thecondenser water-pressure and refrigerant-pressure controlled chambers22,23, is prolonged to enter said yoke from opposite sides in rear ofthe arm 16 and they have inclines or cam faces 30 at their adjacent endsengaging the rear edge of arm 16. Thus abnormal pressure in eitherchamber 22, 23, causing an outward movement of the corresponding pin 28,29 will cause movement of lever 16, 14 suiticient to free the switchand; allow it to fall and open the circuit. It will be apparent thatwith this form also, both or all controlling pressure conditions must benormal to allow the switch to remain closed.

The pressure controlling devices above described may be made adjustableto suit the varyin conditions, and may be provided with signa ingapparatus to indicate return We have the apparatus shown in Fig. 3.

Suitable devices, as for example, springs of any desired form andadjustable if desired in either or both directions by adqusting screwsas shown, may be employed to adi'ust the pressure required for releasingv or ho ding the switches.

' The arrangement is evide tly capable of ex- .tension, by simpleaddition of pressure chambers, &c., to the controlling of theswitch byany number of members. In this way, a pressure chamber controlled by thelow side of the refrigerant circuit may be added. However many suchcontrolling devices are used, all must indicate a normal condition intheir several conduits before the motor can be started and any departurefrom normal con ditions, of a predetermined amount, in any conduit, willstop the motor The pins 28, 29 may be"made' with adjusting'means such asturnbuckles 33, placed on pins 28;, 29 so that their length mav be adjuste'd as required for different con itionsdifferent normal positionsfor example of the respective diaphra ms.

A signal circuit as or example the light circuit 34, may be so arrangedas to give a signal when both or all of the controlling pressureconditions are normal. As here shown the signal-circuit has terminals35, 36, engaged by contacts 011 pins 28, 29 when the diaphragms are innormal position, so completing the circuit through the engaging metalparts 27, 28, 29. I

In .Fig. 4 we have illustrated a further development of the systemwhereby two or more pressure controlled devices coact .in controllingboth the starting and the'stopping of the motor, as for example byclosing and opening of the motor circuit, and we show associated withthe motor controlling circuit, signal circuits for giving warning of theoperative or inoperative condition of the main circuits;-in both mainand signal circuits, the contacts being so arranged that the abnormalcondition of any controlling mechanism will stop the motor and give theappropriate signal, while the restoring of all controlling mechanisms tonormal w1ll start the motor and give another and appropriate signal.

Two pressure controlled devices are shown by way of example at 22, 23',their diaphragm-operated pins 18, 19 hearing con tact or brldge pieces37, under normal conditions of pressure in chambers 22, 23, bridging thespace between brushes 38, 38 and 39, 39 respectively but adapted, by thedevelopment of abnormal conditions in one or both of the pressurechambers to be.

shifted-one or both--to bridge the space between the brushes 40, 40 or41 41-01 both.

here shown applied to a system in which the motor circuit is opened andclosed by-a sole noid arranged in acontrolling circuit. For simplicityof drawing, the rheostats of both the main and controlling switches areomitted. The main or motor circuit is shown at 42, the motor at 43, thecontrollingswitch thereof at 44 and its controllingsolenoid at 45arranged in series with a resistance 46 in a branch circuit 47 from themotor the combined resistance of the solenoid and resistancecoil-beingsuificient to prevent the raising of switch 44.

The contacts 40, 41, are in parallel in a circuit 48 around thesolenoid, and in parallel .with them across 'the ci:rcuit 48 is aswitch'50 which may be hand operated or thermostatically controlled-asby a thermostat placed in a refrigerating chamberand which when placedon contact 51 short-circuits solenoid 45 and opens or keeps open themotor circuit at 44. In the same manner, therlevelopment of abnormaliconditions in either pressure chamber 22, 23 shifting the correspondingbridge 37 between contacts 40 or 41, will short-circuit the solenoid andopen or keep open the motor circuit; The other contact 52 of switch 50is in a branch circuit 53 around resistance 46 in which the contacts 38,39 are arranged in series. When the condition in both pressure chambersis normal, and the branch circuit 53 is therefore closed by bridgepieces 37 at both-38 and 39, and the switch 50 is brought, by hand,thermostatically or otherwise, upon contact 52, the, resistance 46 isshort-cir- .cuited, the lifting power of solenoid 45 is augmented, theswitch 44 closed and the motor 43 started. If now the circuit 53 beopened at any int, as by shifting of switch 50 away rom contact 52 or bythe moving of a bridge-piece 37 from contact with brushes 38 or 39 undera change of pressure in either chamber, the motor circuit may still bemaintained at 44 by even the slight current passing through bothsolenoid and resistance, but ifthe n the solenoid be short circuitedbythe switch 50 being brought in contact with contact 51 or by either,bridge-piece 37 being brought in contactwith brushes 40 or 41, will beimmediately opened at 44 and the motor stopped.

It will, be seen that by adopting a series arrangement for the contactsin branch cir' cuit 53 all of the controlling devices have to be innormal condition in order to en able the motor to be started and that byadopting a parallel arrangement for the contacts in branch circuit 48,the development of abnormal-or sufliciently abnormarl-condition in anycontrollingmechanism will ositively open the motor circuit and stop t emotor if it is'in operation, or will prevent its being started if 1t isnot.

circuit' the motor circuit the other It is also apparent that the systemcould-be expanded to include any additional. number of controllingdevices and that with the arrangement of circuits indicated, bothresistance and solenoid cannot be cut out at once-one or the other isalways in circuit and thus dead short circuits are prevented. As eachmember 37. returns to normal position it not only opens the contacts at40, 41 thus opening the solenoid short circuits 48 and preventing thethermostatic or other switch 50 from short circuiting the solenoid, butit completes at 38, 39 the short circuit to contact 52 around resistance46, so that when the last member 37 returns to normal, it is onlynecessary for switch 50 to move to contact 52 in order to short circuitresistance 46, energize solenoid 45 and start the motor and resume thework of refrigeration.

The arrangement of circuits adapted for the motor controllingcircuit-motor-ciremt opening devices in parallel and motor-circuitclosing devices in series-is followed also in the signaling circuitswhich Wlll now be described. The circuit 54 of local battery 5'5 iscontrolled by a switch 56, closed automatically when the motor circuit15 opened, as for example, bythmshiftrng of switch 50 to point 51. Twobranch circuits 57, 58 from the battery include two signaling devices59, 60preferably dissimilar .111 character, to render their signalsreadily distinguishable audibly or visually or both. In branch circuit57, contacts 61, 62, (corresponding in number to the number of devicescontrolled by abnormal the system), are arranged in parallel andarranged to be closed automatically when any of such devices, moved bythe occurring of such abnormal conditions, opens the motor cont-rollingcircuit. To this end the pressure controlled pins 18, 19, may havenon-conducting lugs or heads 63, adapted, in abnormal position of theircontrolling members, to close the corresponding contacts 61 or 62, andthus give Warning by the signal 59 ofthe abnormal condition. In branchcircuit 58, contacts 64, are arranged in series and adapted to be closedby the lugs or heads 63 when the latter are in normal positionthusindicating by signal 60 whether all of 'the controlling devices whichindicate abnormal conditions-are at normal. The signal 60 mayappropriately be a lam and the signal 59 a bell. If the circuit 54closed at 56 when the motor is stopped by any means, as for exampledirectly by the opening of the motor switch 44, or, as shown, bythe swtch 50 being brought against contact 51 the alarm signal circuit 57canbe completed by closing either of the contacts 61- or 62 while thesignal device 60 will be actuated only by the closing of both contacts64, 65. Thus when abnormal conditions occur and the conditions in motorcircuit is open, closing contact 56, the same abnormal conditions whichhave stopped the motor will close contact 61 or 62 allowing the localbattery current to pass through alarm signal 59. The alarm will continueto be operated until all abnormal conditions have passed and the parts18, 19, 63 have returned to their normal position,

allowing contacts 61 or 62'to be broken.

When all the conditions have returned to normal, provided the motor hasnot been started, so that contact 56 is still closed, the signal circuitwill be completed through 64 and 65 and the operating of signal 60-which may as stated he a light-will indicate that conditions are pro erfor the motor to be again started. The clbsing of the mo tor startingswitch breaks the contact 56 making both si al circuits incomplete andboth alarms an visual signalinopera'tive.

It is obvious that our system as herein described is capable ofconsiderable variation within, the scope of the following claims. Forexample the motor 43 is not necessarily an electric motor. It may be anengine of any desired kind. Theswitch 44 may represent the controllinglever of asteam or hydrocarbon en ine or the switch of the sparkmgcircuit 0 the latter.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is: a

1. In apparatus of the character described, the combination of a motor,a plurality of devices independently responsive to normal and abnormalconditions in the parts of the system, a motor controlling circuithaving means in series controlled to close it to control the starting ofthe motor, by normal conditions in the several parts of the system and amotor controlling circuit having means in parallel to close it to stopthe motor by abnormal conditions in any part of the system.

2. In apparatus of the character described, the combination of a motor,a starting circuit therefor, a stoppin circuit therefor, contacts,arranged 'n series-in the starting circuit, contacts arranged inparallel in the stopping circuit, and means controlled by independentmechanisms responsive to conditions of different par-ts of the system,to close all the contacts in the startin circuit when all the conditionsare norma and to closeone'of the contacts in the stopping circuit whenthe condition in any part of the system is abnormal. i

, 3. In apparatus of the character described the combination of meansfor stopping and starting a motor, a lurality of pressure controlledcontrolling evices for. said stopping and starting means, a signal, andmeans for operating said signal by the conjoint action 0 saidcontrolling devices."

4. In apparatus of the character described,-

the combination of a plurality of devices actuated by changingconditions in different parts of the system, a signal circuit having a)lurality of contacts in series each controlled y one of said devicesand a signal circuit having a plurality of contacts in parallel eachcontrolled by one of said devices. 5. In apparatus of the characterdescribed,

I plurality of contacts in series each controlled y one of said devices,a signal circuit having a plurality of contacts in parallel eachcontrolled by one of said devices and a motor 5 controlling switchcontrolling also both of said signal circuits.

EUGENE CARPENTER. FRED M. KIMBALL.v

the combination of a plurality of devices Witnesses: actuated bychanging conditions indifferent E. J. MGDUFFEE, parts of the system, asignal circuit having a, i L. E. SMITH.

